Main board model: ASUS H110M-K main board
Symptoms: motherboard Won’t Turn On
Maintenance process
ASUS H110M-K motherboard, the fault is that it can’t be turned on. Measure VCC signal according to time sequence:
P_+VCCIO_EN_10 2V is normal;
VCCSA 0.96V is normal;
P_VCORE_EN_10 3.3V is normal;
P_VR_READY_10 is not normal without VCC;
Look up P_VRM_PGD_10.VCC is not normal.
Asus H110M-K motherboard Won’t Turn On repair figure 1.
P_VRM_PGD_10 does not have VCC. This signal is a PG signal sent by CPU power management chip ASP1401B, which shows that there is something wrong with CPU VCC. According to the time sequence, CPU power management chip will send PG when it receives EN and VCC. Let’s find out the conditions for generating VRMPWRGD.
1. VCC VCC 5V of 1.CPU power management chip is normal;
2.P_VCORE_EN_10 3.3V is normal;
3. Measure the VCC VCC of the driver chip of each phase VCC of CPU, and all of them are 12V normal;
4. P_VCORE_DRON_10 This is the signal used to turn on the driver chip. The measured value is 1.19V, which is obviously abnormal, and the normal value is 5 V.
Asus H110M-K motherboard Won’t Turn On repair figure 2.
P_VCORE_DRON_10 is a signal sent by the power management chip to the driver chip, and it will go through a 49.9-ohm resistor to four driver chips. Therefore, if the VCC is low, it is necessary to turn off the 49.9-ohm resistor between the driver chip and the power management chip one by one to see which resistor will restore VCC. If all the resistors are turned off, it may be that the power management chip is broken.Find out the fault point after a wave of analysis operation.
Asus H110M-K motherboard Won’t Turn On repair figure 3.
Measure P_VCORE_DRON_10 VCC again after disconnecting this resistor.
Asus H110M-K motherboard Won’t Turn On repair figure 4.
P_VCORE_DRON_10 VCC is back to 4.86V normal, which means that the driver chip of integrated display VCC is damaged, which leads to the lowering of P_VCORE_DRON_10 VCC. Replace the damaged driver chip NCP81166A(PU201).
Asus H110M-K motherboard Won’t Turn On repair figure 5.
After the replacement of the measuring CPU VCC, it was not surprising that it had already happened.
Asus H110M-K motherboard Won’t Turn On repair figure 6.
Plug-in, start-up, easy lighting, troubleshooting and maintenance are over.
